Beast of a cooker

[brizospark]

OK I know this has already been covered but I have been asked to install a supply and isolation switch to a Rangemaster cooker which has a rating of 14kw.

This cooker has a couple of ovens and grills and induction hobs - it's a beast

My question is regarding the cable / isolation switch rating, I know there is some debate over the issue but I reckon being realistic there is no chance that the cooker will ever run at full capacity and that a 6mm cable covered by a 40a MCB (only 5m run from board no insulation under floor) and a 45a DB switch would suffice.

The other option would be a 63a MCB with 10mm cable and a 63a rotary isolator.

The house is occupied by a couple and soon to be baby.

What would you guys do in this situation?

 

[jaypp]

harmonising, so I was lead to believe, meant manufacturers could supply us with the same products as europe. this equates to lower production costs

 

[Badged01]

.....It's 230 because our European masters decided we should lower our voltage to harmonise with the rest of Europe .....

We haven't lowered voltages we've just incorporated a tolerance band of 230V +10% or -6% (e.g. 216V to 253V). So both 230V and 240V are acceptable ...... 230V is just taken as the value to be used for theoretical calculations!

 

[davesparks]

We've always been supplied with the same products as Europe as far as voltage rating goes, appliances have been rated for 220-240 nominal for years. They still have to manufacture them exactly the same as max voltage is still 253V.

 

[jaypp]

We've always been supplied with the same products as Europe as far as voltage rating goes, appliances have been rated for 220-240 nominal for years. They still have to manufacture them exactly the same as max voltage is still 253V.

OK bud, I stand corrected regarding this. I never thought that 'actual' supplied V changed by the way!!

 

[davesparks]

The only real exception I have come across is lamps, especially for theatrical lighting. We are increasingly getting lamps rated at 230V rather than 240V which has a major impact on lamp life when dealing with a 2KW halogen lamp!

 

[Engineer54]

This same old chestnut yet again!!! .... Up to 15KW, 6mm on a 32A breaker will more than suffice, and has been doing so for more than 60 years now (7/044 -30A ''3036 fuse/MCB'')... That includes every Xmas day/Boxing day family dinners and every other family scenario dinners.

Now to wait for the exact the same question/discussion, same time next week or the week after!!

 

[davesparks]

There are a couple of exceptions to the rule that I have come across, and they are ridiculously huge commercial style cookers being sold to people with too much money and a love of massive stainless steel appliances.
But then the manuals are pretty clear about the requirements.

 

[Engineer54]

There are a couple of exceptions to the rule that I have come across, and they are ridiculously huge commercial style cookers being sold to people with too much money and a love of massive stainless steel appliances.
But then the manuals are pretty clear about the requirements.

If they are 15KW or less, there are no exceptions to the formula!!

 

[davesparks]

You've never had to deal with Wolf cookers then. Self clean mode is ridiculous on the buggers! I've fallen fowl of them more than once now.
It's a ridiculous design on my opinion, the two I had issue with had a self clean mode which turned the whole appliance to full at once.
I don't know if it's the manufacturer giving an 'after diversity' rating in the manual or something else.

 

[Engineer54]

If the cooker is rated 15 KW or less, what's the problem?? Any self cleaning mode will apply to the oven section(s) only, no such thing as a self cleaning hob, you'll just burn any spillage harder onto the hob element faces... That's a big whack off the 15 KW connected load...

 

[Geoffsd]

Originally Posted by GeoffsdNot quite.

14000/240 = 58.33

58.33 - 10 = 48.33

30% of 48.33 = 14.5 + 10 = 24.5A

+ 5A if socket.

should be 230 no?should be 230 no?

No. It's not because 240 is the actual voltage.

It is because that is what the manufacturer will have quoted - 14kW @ 240V


If you want to use 230V then you will have to adjust the power as well.

This will make the current even less. 12.8kW @ 230V = 55.8A

After diversity 23.74A.


So, a 32A MCB is fine and so would be 4mm cable (method C).

6mm is a remnant from 30A 3036 fuses and their derating factor.


As Tel said in the first reply 6mm and 40A MCB - no problem.

 

[SPARTYKUS]

I know that diversity is applied for a cooker circuit, but what happens at Christmas for example, when she is running full tilt?

Even then, rings and heating elements cycle. They get to heat and switch off for a bit. Hence the diversity thang.

 

[HappyHippyDad]

Even then, rings and heating elements cycle. They get to heat and switch off for a bit. Hence the diversity thang.

Unless you're a student!!

Remember when I was 19 our immersion never worked in the student house so we had huge saucepans of water on every ring (for a bath!) switched on at the the same moment up to the max, plus as many casserole bowls filled with water in the oven...

Students!! taking diversity to the max!

 

[davesparks]

That won't change a thing as the elements will still be cycling on and off.

 

[davesparks]

If the cooker is rated 15 KW or less, what's the problem?? Any self cleaning mode will apply to the oven section(s) only, no such thing as a self cleaning hob, you'll just burn any spillage harder onto the hob element faces... That's a big whack off the 15 KW connected load...

Jobs are irrelevant in this case as they are gas.
The self clean mode brings all of the oven elements on at once and takes a 45A mcb out after a while of running. the manufacturers spec has max load as 50A.